The Iron Curtain is often touted as an exception to the general trend of global integration in the 20th century. However, as Erik Scott points out in his recent book on defectors, the concept of a monolithic Iron Curtain does not reflect the realities of the era. Strict border regimes were not simply imposed by one side—i.e., the Soviets and their allies—but existed on both sides. The Cold War superpowers used their global reach to restrict the mobility of people entering and leaving countries while facilitating certain types of privileged migration through highly managed checkpoints. As Scott remarks, "Both sides shored up borders to regulate movement in previously ungoverned spaces across the globe, targeting liminal areas favored by those fleeing the socialist bloc." Each border regime favored certain types of crossers. For instance, the U.S. accepted only political refugees or defectors and did not guarantee entry. In contrast, the Soviet sphere was desperate to repatriate its own citizens and prevent unauthorized emigration. Borders were "thick zones of categorization and control," whose power was reinforced by technological advances in espionage and vast amounts of human labor. Borders became in-between spaces, "states of exception" (Agamben) or "rites of institution" (Bourdieu). This roundtable will explore the "battle over borders" in Cold War history and culture through case studies of defectors, espionage and counterespionage operations, illegal escapes via hijackings, "flight helpers," and reverse crossings from West to East.